This invention relates to wireless telephone networks and more specifically relates to a wireless network utilizing packet switching and Internet protocol (IP) packets to provide communications with wireless telephone users that do not have a static IP address.
Wireless telephone networks continue to evolve. In the United States, wireless telephones in the public switched telephone system (PSTN) began with the mobile telephone system (MTS) that utilized lower frequencies for radio frequency transmissions and carried voice communications by analog signals. The MTS was spectrally inefficient in that a single frequency or channel was used to cover communications over a large geographic area. The wireless cellular telephone system provided an improvement by utilizing the concept of smaller geography cells that allowed communication channel frequencies to be reused in relatively nearby cells. The cellular system evolved from carrying communications by analog signals to digital signals. Various types of digital signaling have been, and continue to be, utilized including time division multiple access (TDMA) and code division multiple access (CDMA) signaling. With the growing popularity of the Internet and the use of IP addressing for routing packets to a destination device, many wireless devices accommodate both voice communications using a digital signaling protocol and data communications using packets with IP addressing.
As networks continue to evolve, some networks, e.g. third generation universal mobile telecommunications systems (3G—UMTS), offer voice communications carried by packet switching and IP addressing. Due to limitations of the current IP addressing scheme (version 4), it is not possible to assign unique static IP addresses to all devices on the Internet. Where a mobile user desires to initiate a call using packet switching and does not have a static IP address assigned, a dynamic IP address can be assigned using dynamic host configuration protocol (DHCP) or other mechanisms to identify the mobile user during the call session. An IP address for the mobile user is required since packets carrying communications from the called party (a network user) to the originating mobile user will utilize the mobile user's IP address for return packets carrying communications to the mobile user. However, difficulties arise when it is desired to originate a packet switched call from a network user to a mobile user that does not have an assigned static IP address. Unless the mobile user's device is registered and has been assigned a dynamic IP address prior to the initiation of the packet switched call to the user, such calls cannot be made since an IP address of the mobile user's device is not available to the packet switch even though the originating party may know the directory telephone number (DN) of the mobile user. Thus, there exists a need for a solution to this problem.